Safety Effectiveness of Speed Limiters

Understanding speed as a highway safety issue necessitates accurately defining the relationships between speed limits, travel speeds, and safety. Additional data is needed to evaluate adaptive speed control systems for altering vehicle speed based on roadway conditions and the appropriate speed limit. Joining before-and-after test focusing on the safety benefits of adaptive speed systems provides an important opportunity for FMCSA and carriers to work together on research design and implementation efforts, with the shared objective of improving safety. This type of testing requires a commensurate effort to collect and share valuable data. In addition, FMCSA would facilitate testing and information sharing by developing a systematic way to collect and evaluate data from before-and-after testing that would typically exceed the available resources of industry stakeholders. As a result, the purpose of this project is to identify safety impacts of adaptive speed control technologies for adjusting vehicle speed to the posted speed limit. This project will be conducted in cooperation with NHTSA and the Federal Highway Administration (FHWA).